Friction head for rifle bars



April 5, 1927. 1,623,411

G. w. HULSHlZER FRICTION HEAD FOR RIFLE BARS Filed Sgpt. is, 1925 E (7#1 1 g 1 f 11 42 Y M- Y 1 INVEN TOR.

Patented Apr. 5, 19 27.

' Nir p j GEORGE w. HULSHIZER, or sTEWARTsvILLn, iinw annsny nssrelvon'roinennsonn RAND COMPANY, or JERSEY CITY, new JERSEY, A CORPORATION OFNEW JERSEY. 1

mama :HEAD'FOR RIFLE Bans] ,Application filed September 16,1925; SerialNo. 56,567. t

i :Q This invention relates to rock drills, but

' more particularly to a device for imparting rotative movement to thedrill steel of a 'fluid actuated rock- ,drill of the hammer Hyp -P I V.Oneobject of the inventionjis'to hold the rifle :bar of a rock drillimmovable so that the hammer piston and the associated rota- .jtiveelements will describe a partial revolu- 1o jti'onwhenthe pistontravels' in one direcf 7 f'jtionl andtoinsure'instant and positive retijonsf of elements, features of, construction, I 25 and arrangement ofparts havln'g the general model of o eration substantially as herein-.

' after described andmoreparticularly pointlfledjout in the appendedclaims and illuslfltratedflin the accompanying, drawings, in 36'which\'j, j i w 'Figure 1 is a longitudinal sectional ele- 'vation of arock drill showing the friction I ,head "in releasingposition, and

1 Eigurefljisfa view similar sho'wingthe friction head in engaging posi-V tion with the friction ring; I v r r Referring to'the drawings, theinvention is shown embodied in a rock drill having acylinderl A,a fronthead B and back fhead C,

40' which partsform the'outer casing for the rock-drill and are held inoperativenposition y by the; usual side bolts -(not shown). Thefcyl'inderA is provided with apiston D havfinga'forward fluted extensionE which col,operatesj slidably with a correspondingly fluted chuck nut Fin the front end of the cylinder A, The chuck nut F is arranged ro-""tatably" within the cylinder and has at one end clutch teeth G whichcooperate with p'artfJ to prevent relative rotation between said chucknut and chuck'part J. Frequentqfizist seeige eqo d' chuc Par K is emp oy.Vfland; W leading from the rear andfr'ont to Figure 1 similar clutchteeth H formed on a chuck :.erabl y "somewhatsmaller than tlle biore clso .ith twh n gcsaid h dzis n the re leaaiesir and is arranged in thefront 'endof the front headB to receive a drill steel L and hasinterlocking teeth 0 which engageisimilar teeth P formed on the forwardend of the chuck part J to prevent relativeiirotation between the chuckparts. The chuck part J also serves as; a seat for ananvilblockQiarranged slidably therein to transmit the blows of thehammer piston D to the drill steeliLi Pressure fluid for actuating gthejhainmer j piston D and other associated partsrad mitted into the drillthrougha,suitable connection R secured to the valve chest S and iscontrolled by a' suitable throttle 'valvelnot shown) having a throttlelever T." The dis- 7 tribution of the pressure fluid may be con trolledby any suitable valve. In this instance a flipper valve U is indicated lf The flipper valve U controls the admission ports ends ofthe valvechest' S to the'corre sponding'ends of the cylinder Theexhaustofpressure'fluid from the'cylinder A is effected through a freeexhaustpiort Xc'om. trolled by the pistonZD; p v if, c,

In order 'to impart rotative movement to the piston D' andassociatedrotative' parts, a fluted rifle bar.Yi cooperates with grooves Zformedin, the pistonto prevent relative rotation between said piston andsaidrifle bar. wback cylinder washerfbforms a cover f'orthe rear endofthe cylinder A and also 'serves to centralize the rifle barfYQ Althoughthe rifle bar is shown flutedlit'fis'to be understood that anyfsuitableform offbar may be used which will prevent relative rotative movementbetween the bar- Yand the piston, and which will causethepiston todescribe a partial revolution during one-:01" the other of its strokes.

In accordance withthe present inventiona friction ring 0 is arrangedintthelb ack'fhead C and has a tapered borecZJ Thejfriction ring 0 maybesecured in position in any suiable manner, as i for instance, a, doweljoins, a key, or press fitted as indicated in. the. dr wi rearward partof the friction ring-c and communicates with" the rearw ard end of theii?- cylinder A 'througha passage The rifle bar Yicarries at itsrearmo'st end a friction head 9 tapered'to correspond with the taper ofthe friction ring 0., Thehead g is-preftfizarn EH 1? i A chamber e is"formed in the" H t" Wardly ofrtheplungers 2. haustedto atmospherejthrough. the ports j V sition -shown in; Figure 1, a slight space Iteicists between the periphery of said head and the'bo're cZ.Communication :between o v *saiid spac'e h-and'theatmosphereuisprovidedI flw5 by a-port j ,fo'rmed in the .frictionl ;ring 0,

*a passage is in the'back head C, and a port extending from thepassagekrto the 8X1 terior. of the hack head ,0. In this instance thechamber 6'i1S' also"in'commuii cation 'O with the port 0.through a small.port or vent,

V p iormed in the rearward end of the-fr ction f ,ringc toprovide fortheescapeo fair com pressed'iby the piston during its rearward,.,Stroke.,

v i. {Betheendytha'ttheflhead g cofitherifiehar naybe:automaticallyiorced into engagev .me t with .theltaperedlboreicl {ofthe fricti ring 0, a plurality {of .plungers gar-e; arranged i1-slidahlyin hores ,4 and Joe/arm .Qne' end ge ns .the hack cylinder 2Springsls are' arranged 'inthe'hore T1631- fers loiitwardly against .t ecylinder :WaShQ ixflhgoperation of the device is .as follows In ,the psition 01 the par s shown an Fig- 1 nre.=l', arportioniofithelpressure,fiuid iiIithe rearward end ofthe .ycylinder- A will pass;

through; the passage fintothe .chamher'e and act against the rearwardsurface of the ,head ,9; In thisflvvay the head ig will: be forceddoWmvardlyor forwardlyagainst the :backrcylinderwasher bkas shown 1111Figure v l 1. It'iwill be seen that when therhead gkis in this position,it' is'outcof' enghge'mentwith .3; ,thebore dendiewiieiad 9 togeth r ithe .rifle'bar mayqthen desoribe a partialrevolu i Q ,tion ,as'the'piston Dadvanceson its forward stroke; ,VVhilethe friction head ig.isJoeing held free .from the tric'tion ring e, ,aeportion 10f the,pressure fluid in the chamber 6 isexy an d p, the passage 7:: and the,port 0 toimmediatelylreduce the ,pressureacting against ithe headfgbelow line pressure; After .the

i ,pisftonjl) uncovers the free exhaust ;port X,'

'the,pressure fluid remaining in the chamber. 3 '0 will beiexhaustedthrough the passage or 1-, passages ,f, t ro gh the cylind 7 A n lsmain'exhaust port ,X- to}the atmosphere as well as through lthepassagesleedingdirectly 'i{,fromthechambereto the atmosphere.

; S iinultaneously Withlthe exhaust of the pressure :fluid gfromwthechamber .16 .ihe springs s illuforce-the .head ,9 into engageent with:the tapered h r-ed i o t fricti n ring When' the p is to n starts onits rear w rd lstroke, aJSl gh-t iturningv -motion isi -v it partedtothe riflefhar which causesthehead g g to more firmly engage vthe tapered,hore d. zBy t usgho fcling he rifi'eibara ta i na y the ;;pi5ton 1)during its rearward stroke will. .move in yaspira l {direction about{the jrifiecbar ,andsince the pistoniand the.ch c ..pa s 1 are ;inter0cked against ;I?ela'tive irotative 'movement', the drill steelL isrotated tofa' {blow of the piston.

Washer 12. V

to hold said 'plungv different "cutting position for the succeeding Theforegoingdescribed device has been found .to he unusually .eflicient inoperation and possesses the desira hle iadvantage of permitting the head9 to slip Within the tapered bore d When the drill steel becomes In suchcase the stuckin the drill hole. drill maybe slightly Withdravvn'and thepiston illmaycontinue to reciprocateuntil the i -drilllsteelL hasbecomeloosened'in the hole.

After the drill steel L'isaga'in freeto rotate, the .dl ll in y beadvanced an th ri t o heady and other parts comprising the rota-:tive.ele ment Will again function in their normal manner. of thisinventionfis that the ear Which'in An ther desira le advantag 7 [theordinary rifle .bar head and associated par is usually 0 11131 41 to .afew rath r small wearing surfaces, may he.o f mem- ,para-tiv yllalgge ara'so .thatzt e li e Qfthes parts may render a long period of service ascompared ras er. v

.1 Claim? Y or 1. In ,fluid actuatedfrock drill, theQCQmhination' of acylinder, a; reciprocating ham rmer ,pistonin the cylinder, aihack'headfor the cylinder, a friction ringsecured fixedly in the hack head. andhaving 'aytap'ered bore, a friction head rotatahlefllid IOIigitHdin'ally,movahlein' the friction ring, a riflegbar carried ,hy the ffrictionheadand extending slidivith the usual devices of this char- (ably intothehamlIlQr pistomspring pressed :p1ungers{.i11 :the friction head adaptedto ,hear continuously upon some ;non .ro'tatable element ol the drillfor-moving said head into frictional engagement with the tapered bore inorder to hold the rifle barfaga'inst r ta i n during -rearwa d s rokeTof the piston, a pressure. chamber communication 'With' the cylinder,to, ,receiVe pressure fluid .iforactuating the friction head (out ofengagemen f o t e riction ring When-t e hammer piston starts gon'itsforward stroke, and ,a ,passage n the ifriotionrlng t0 estab- .lishcommunication .loe't-Ween the tapered bore and ,the atmosphere forpreventing air compressed hywthe piston ffromlunseating the frictionhead.

friction :head hearing against :the cylinder hack head and adaptdtomovethesaid fric.-' tmn head m e hgagem n wit t t per d bore for holding therifle bar against'rotation during the rearward stroke of thepiscommunication between the tapered bore I ton, and a pressure chamberin the friction and the atmosphere for reventing air comringcommunicating with the cylinder to repressed 'by the piston rornunseating the 10 ceive pressure fluid for holding the frietlon frictionhead; 7

5 head free in the friction ring during the In testimony whereof I havesigned this forward stroke of the hammer piston, and specification. apassage inthe friction ring to establish GEORGE W. HULSHIZER.

